Syringe-filling medication dispenser

Abstract

A medication dispenser (2, 120) is used to directly fill a syringe (8, 134) with measured amounts of one or more liquid medications, typically two different types of insulin, from vials (4, 130) each having a septum at one end. The septum of each vial is pierced by a pair of hollow spikes (54, 56, 140, 142). One of the spikes is used to allow the liquid medication to be pumped out of the vial while the other spike is used to introduce air into the vial to replace the withdrawn liquid medication. Using a reciprocating piston-and-cylinder type pump, the vials are pressed a desired number of times according to how much medicine is to be driven into the syringe. The invention permits insulin users the freedom to quickly and easily select the proportions and amounts of insulin to be injected depending upon the user's current needs.

What is claimed is: 
     
       1. A medication dispenser, for use with a container containing a liquid medication and a syringe of the type including a needle cannula, a barrel and a plunger, the dispenser comprising: a body to which the container and the syringe are mountable;   dual port means for providing gas and liquid ports into the interior of the container;   and a reciprocating pump assembly having a cylinder and a piston, the pump assembly fluidly coupled to the container by the liquid port and spaced apart from, and fluidly coupled to the syringe by a fluid path, the piston being movable from a first position to a second position to withdraw the liquid medication from the container, through the liquid port and into the cylinder, the withdrawn liquid medication being substantially simultaneously replaced with a gas which passes into the container through the gas port, the piston being movable from the second position back towards the first position to force a predetermined volume of the liquid medication along the fluid path and into the needle cannula of the syringe.   
     
     
       2. The dispenser of claim 1 wherein the body includes cavities for housing the container and the syringe. 
     
     
       3. The dispenser of claim 1 wherein the dual port means includes septum-piercing, hollow spikes. 
     
     
       4. The dispenser of claim 1 wherein the pumping means includes means for metering the amount of the liquid medication pumped into the syringe. 
     
     
       5. The dispenser of claim 4 wherein the metering means includes means for preventing the pumping of the liquid medication into the container. 
     
     
       6. The dispenser of claim 1 wherein the fluidly directing means includes a septum pierceable by the needle cannula. 
     
     
       7. The dispenser of claim 1 wherein the pumping means includes a piston and cylinder assembly. 
     
     
       8. The dispenser of claim 7 wherein the pumping means is actuated by reciprocal movement of the container. 
     
     
       9. The dispenser of claim 8 wherein the piston and cylinder assembly includes a cylinder and a piston, coupled to the container, for reciprocal movement with the container within the cylinder between a delivery position and a replenish position, the cylinder having a cylinder wall. 
     
     
       10. The dispenser of claim 9 wherein the pumping means includes a check valve fluidly coupling the container and the cylinder. 
     
     
       11. The dispenser of claim 10 wherein: the check valve includes a flapper element which frictionally engages the cylinder wall as the piston moves between the delivery position and the replenish position;   the friction between the cylinder wall and the flapper element being sufficient and the flapper element constructed to cause the flapper element to seal the cylinder from the container and to fluidly couple the cylinder to the container when the piston moves towards the delivery position and towards the replenish position, respectively.   
     
     
       12. The dispenser of claim 1 wherein the fluidly directing means includes a supplemental check valve which permits fluid flow from the liquid port to the needle cannula but prevents fluid flow from the needle cannula to the liquid port. 
     
     
       13. The dispenser of claim 1 wherein the fluidly directing means includes a resilient pathway element having a flow surface which can deflect according to a fluid pressure applied thereto. 
     
     
       14. The dispenser of claim 13 wherein the resilient pathway element includes an elastomeric material supported on a support surface containing a groove, the elastomeric material being deflectable into the groove thereby deflecting the flow surface. 
     
     
       15. The dispenser of claim 1 wherein the fluidly directing means includes accumulator means for providing a pressurized liquid accumulation region to accommodate any flow restriction created by the needle cannula. 
     
     
       16. A multiple medication dispenser, for use with first and second containers containing first and second liquid medications and a syringe of the type including a needle cannula, a barrel and a plunger, the dispenser comprising: a body to which the first and second containers and the syringe are mountable;   first and second dual port means for providing first and second gas and liquid ports into the interiors of the first and second containers;   first means, spaced apart from the syringe, for substantially simultaneously pumping the first liquid medication from the first container through the first liquid port and replacing the pumped first liquid medication with a first gas which passes into the first container through the first gas port;   second means, spaced apart from the syringe, for simultaneously pumping the second liquid medication from the second container through the second liquid port and replacing the pumped second liquid medication with a second gas which passes into the second container through the second gas port;   means for fluidly directing the first and second liquid medications from the first and second pumping means to the needle cannula;   whereby the first and second liquid medications are pumped from the first and second containers by the first and second pumping means, through the needle cannula and into the syringe.   
     
     
       17. The dispenser of claim 16 wherein: the first pumping means comprises a first piston and cylinder assembly and is actuated by reciprocal movement of the first container;   the first piston and cylinder assembly includes a first cylinder and a first piston, coupled to the first container, for reciprocal movement with the first container within the first cylinder between a first delivery position and a first replenish position, the first cylinder having a first cylinder wall;   the first pumping means includes a first check valve fluidly coupling the first container and the first cylinder;   the first check valve includes a first flapper element which frictionally engages the first cylinder wall as the first piston moves between the delivery position and the replenish position; and   the friction between the first cylinder wall and the first flapper element being sufficient and the first flapper element constructed to cause the first flapper element to seal the first cylinder from the first container and to fluidly couple the first cylinder to the first container when the first piston moves towards the first delivery position and towards the first replenish position, respectively.   
     
     
       18. The dispenser of claim 17 wherein the fluidly directing means includes accumulator means for providing a pressurized liquid accumulation region to accommodate any flow restriction created by the needle cannula.